Phillips, Flat, Thread Rolling Screws. Thread Rolling Taptite thread for drilled, punched or cored holes in all ductile metals and punch extruded metals. Eliminates chips, requires low drive torque and is resistant to vibrational loosening. Flat head screws are used when protrusion of the fastener above the mating surface is unacceptable. Typically 100 degree flat or for fastening softer materials, 82 degrees flat.